Comment by piccolbo

Second that but there is no matplotlib underneath AFAIK. It does html based interactive graphs using a variant of the grammar of graphics, with extensions for interactions. Grammar of graphics means a great, proven (see ggplot) compromise of power and simplicity. <shameless plug> If you need a library of one-liners built on top of altair (that is if you need some standard stats graph) I wrote altair_recipes (https://github.com/piccolbo/altair_recipes/ or pip install altair_recipes) for that. </shameless plug>